Videoconferencing, or video calling, has been used to supplement, and in some instances, to replace the traditional face-to-face meeting between people from different physical sites or locations. When properly implemented, videoconferencing can reduce real and opportunity costs to businesses because it cuts down on the travel time and cost required to bring personnel from different locations together for a face-to-face meeting.
As known in the art, videoconferencing or video calling includes the transmission of captured video images between the parties involved. Typically, a captured video image includes two portions: a) a foreground portion that shows the intended object of interest, such as a person or a business presentation involved in the videoconference; and b) a background portion that shows the surrounding environment, such as an office or a location, in which the object of interest is situated. In some instances, videoconferencing parties may be concerned about the improper disclosure of their surrounding environment for security and/or aesthetic reasons. There is also a technology concern of having to maintain an expensive video image transmission bandwidth that may be wasted in transmitting unnecessary background information in a captured image or risk a slow down in the image transmission that may affect the quality of a videoconferencing session.
To remedy the aforementioned problems of capturing unwanted background image information for transmission, typical videoconferencing or video communication systems employ a single distance threshold or color distributions to determine where the background and foreground portions of video images are. The background portion of each video image is then replaced as desired. However, with the use of a single distance threshold, there are instances where one or more parties involved in an imaging application, such as a videoconference or a video call, may be considered part of the background and removed from the video image of the video call. For example, consider a scenario where a person is sitting in a reclining chair while participating in a video call, and a single distance threshold is set behind the chair. Then the resulting virtual depth surface partitioning a transmitted foreground portion and an image-removal background portion of the image would typically be a plane perpendicular to the floor and ceiling, behind the chair. If the person reclines in the chair at a 45-degree angle to the floor, the resulting video image presented to other remote parties involved in the video call would include only the part of the chair and the part of the person that is in the transmitted foreground portion in front of the capture plane. The rest of the chair and the person would be replaced with alternative image information.
Likewise, with the use of color distributions to determine where the where the background and foreground portions of video images are, if the person involved in the video call happens to wear clothing with a color distribution that matches the color distribution of the background, a part or an entire image of the person may be replaced with alternative image information.
Accordingly, there is a desire to effectively replace the background of images in an imaging application, such as a video call, while allowing a call participant to move freely about the camera without the risk of blending the call participants into the background portion and partly or completely eliminating such call participants from the ongoing video image in the video call.